In U.S. Pat. No. 4,477,399 dated Oct. 16, 1984 there is disclosed a plurality of inflatable annular tubes employed for masking the wiring and electrical devices in an electric water heater to prevent foamed insulation material, injected between the inner tank and outer shell, from coming into contact with the electrical devices associated with the heater.
While this masking arrangement has been satisfactory for its intended purpose, it has been characterized by certain disadvantages in that each inflatable annular tube has to be mounted individually around the electrical devices, thus, increasing the time required to mask the electrical devices before the injection of the insulation, and there is no provision for masking the fittings having threaded bores on the inner tank to prevent the insulation from contacting the bore threads to which the various nipples for the cold and hot water lines and drain valve, are threaded.